Progressive Cavity Pump/Motor Drive Mechanism

Abstract

A progressing cavity pump has a rotor that moves in an eccentric motion, and is driven by a drive shaft that rotates about a fixed axis. Various means have been used to connect the two; mostly using an intermediate shaft called a connecting rod that has a universal joint at either end. This device replaces that with two parallel plates; one with several pins protruding from it, and the other with the same number of holes in it. The holes are sized to allow the eccentric motion of the rotor. There is also a ball between the two plates to transmit loads between the plates.

What is claimed is: 
     
         1 . A drive coupling mechanism, comprising:
 a first plate configured to couple to a shaft having a fixed axis;   a second plate eccentrically disposed adjacent to and spatially separate from the first plate, the second plate configured to attach to a rotor having an orbiting axis, wherein a rotation of the rotor produces a circular path of the orbiting axis with a diameter of eccentricity;   one of said first plate and said second plate including a first cylindrical bore wall defining a first bore extending longitudinally towards the other one of said first plate and said second plate;   a first pin having a first end attached to said other one of said first plate and said second plate, said first pin extending into said first bore and abutting the first cylindrical bore wall, said first pin having a pin diameter, said first bore having a bore diameter, said bore diameter being at least equal to the pin diameter plus the diameter of eccentricity of the orbiting axis to allow rotation of the rotor and the shaft via the drive coupling mechanism.   
     
     
         2 . The drive coupling mechanism of  claim 1 , further comprising a spacer between said first plate and said second plate to keep said plates spatially separate. 
     
     
         3 . The drive coupling mechanism of  claim 2 , said spacer including a bearing. 
     
     
         4 . The drive coupling mechanism of  claim 3 , one of said first plate and said second plate including a recess for containing the bearing. 
     
     
         5 . The drive coupling mechanism of  claim 4 , the other one of said first plate and said second plate including an annular grove within said plate and aligned with the bearing to allow the bearing to roll around in the annular grove during rotation of said first and second plates for parallel movement between said first and second plates. 
     
     
         6 . The drive coupling mechanism of  claim 5 , said annular grove having a mean diameter substantially equal to the diameter of eccentricity of the orbiting axis. 
     
     
         7 . The drive coupling mechanism of  claim 1 , said first end of the first pin being attached to said first plate, said drive coupling mechanism further comprising a securing ring adjacent said second plate opposite said first plate, said first pin having a second end opposite the first end and extended through said first bore, said securing ring attached to the second end of the first pin. 
     
     
         8 . The drive coupling mechanism of  claim 1 , said one of said first plate and said second plate that includes the first cylindrical bore wall further comprising a plurality of additional cylindrical bore walls, each of the plurality of cylindrical bore walls defining an additional bore extending longitudinally towards the other one of said first plate and said second plate, the drive coupling mechanism further comprising a plurality of additional pins, each of the additional pins attached at one end thereof to said other one of said first plate and said second plate, each of said additional pins extending into a respective one of said additional bores and abutting the respective additional cylindrical bore wall, each of the additional pins having a respective pin diameter, each of said additional bores having a respective bore diameter being at least equal to the respective pin diameter of the respective pin extending into the respective additional bore plus the diameter of eccentricity of the orbiting axis. 
     
     
         9 . The drive coupling mechanism of  claim 1 , further comprising a connecting rod axially fixed to said first plate, said connecting rod being configured to attach said first plate to the shaft. 
     
     
         10 . The drive coupling mechanism of  claim 9 , further comprising a shaft clamp that fixedly secures said connecting rod to the shaft. 
     
     
         11 . The drive coupling mechanism of  claim 1 , said first plate being fixedly attached to said shaft. 
     
     
         12 . The drive coupling mechanism of  claim 1 , said shaft being a drive shaft. 
     
     
         13 . A method for coupling a shaft having a fixed axis to a rotor having an orbiting axis, wherein a rotation of the rotor produces a circular path of the orbiting axis with a diameter of eccentricity, the method comprising:
 attaching a first pin to a first plate, with the first pin extending perpendicularly from the first plate, the first pin having a pin diameter, a first end and a second end opposite the first end, with the first end being attached to the first plate;   placing a second plate adjacent to and spatially separate from the first plate, the second plate having a first cylindrical bore wall defining a first bore that extends longitudinally towards the first plate, the first bore having a bore diameter that is at least equal to the pin diameter plus the diameter of eccentricity of the orbiting axis;   depositing the first pin into the first bore and abutting the first cylindrical bore wall of the second plate while maintaining a spatial separation between the first plate and the second plate;   fixedly securing one of the first plate and the second plate to the shaft having the fixed axis; and   fixedly securing the other one of the first plate and the second plate to the rotor having the orbital axis, the shaft and the rotor being coupled via a drive coupling mechanism including the first plate, the second plate and the first pin to allow rotation of the rotor and the shaft via the drive coupling mechanism.   
     
     
         14 . The method of  claim 13 , further comprising dispensing a spacer between the first plate and the second plate to maintain the spatial separation there between. 
     
     
         15 . The method of  claim 13 , further comprising extending the second end of the first pin through the first bore, and attaching the second end of the first pin to a securing ring adjacent the second plate and opposite the first plate. 
     
     
         16 . A progressive cavity device, comprising:
 a stator defining a helically convoluted elongated chamber;   a rotor within said stator, said rotor including a helically shaped shaft and a plurality of lobes with a profile that compliments the helically convoluted elongated chamber of said stator, said rotor having an orbiting axis, wherein a rotation of the rotor produces a circular path of the orbiting axis with a diameter of eccentricity; and   the drive coupling mechanism of  claim 1 , said second plate being fixed to said rotor.   
     
     
         17 . The progressive cavity device of  claim 16 , further comprising a spacer between said first plate and said second plate to keep said plates spatially separate. 
     
     
         18 . The progressive cavity device of  claim 16 , said first pin having a first end attached to said first plate, said drive coupling mechanism further comprising a securing ring adjacent said second plate opposite said first plate, said first pin having a second end opposite the first end and extended through said first bore, said securing ring attached to the second end of the first pin. 
     
     
         19 . The progressive cavity device of  claim 16 , said one of said first plate and said second plate that includes the first cylindrical bore wall further comprising a plurality of additional cylindrical bore walls, each of the plurality of cylindrical bore walls defining an additional bore extending longitudinally towards the other one of said first plate and said second plate, the drive coupling mechanism further comprising a plurality of additional pins, each of the additional pins attached at one end to said other one of said first plate and said second plate, each of said additional pins extending into a respective one of said additional bores and abutting the respective additional cylindrical bore wall, each of the additional pins having a respective pin diameter, each of said additional bores having a respective bore diameter being at least equal to the respective pin diameter of the respective pin extending into the respective additional bore plus the diameter of eccentricity of the orbiting axis.